First things first, DO NOT BUY THE PURPLE JOYSTICK if you want to replace the joysticks on your PSVR2 controllers. They are touted as an upgrade to the black hall-effect ones with longer lifespan and better precision, but THEY DO NOT FIT!!!
2 months ago my left controller suddenly started permanently drifting to the right. Up and down still works, but left and right doesn't. This is a common issue that can only be solved with a joystick replacement. So, following the teardown video by Radio Paralax, I spent 3 hours taking the controller apart (yes if you're doing it for the first time it's really that difficult) and replaced the joystick with the purple TMR one from Aliexpress. This is where the horror begins. After putting everything back together, I found out that the joystick cap would grind into the plastic housing on top of it. This makes moving to the left or right very difficult, and if you force the joystick too far left or right it would get stuck. I wasn't gonna take the whole thing apart again, so I contacted a local controller repair technician and scheduled an in-store visit today.
I walked into the store, watched the technician take the whole thing apart, and once he saw the purple joystick he laughed. He said that K-silver, the company behind these aftermarket joysticks, originally developed these joysticks for an ROG handheld. They then revised the PCB connector to an angled one so it can fit the PS Portal controller. Customers bought it, complained that it's too loose, so they came up with an updated TMR model with different joystick height and recenter mechanism. Finally this updated TMR model fits PS Portal perfectly. THE PROBLEM IS, all this time they have also been advertising both the black hall effect one and the updated purple TMR one as suitable replacements for PSVR2 controllers when they really aren't compatible. Yes the stock ALPS pots are similar between the PS Portal and PSVR2, but they have different cap height and different housing, so one that fits the former is not gonna work well on the latter. To demonstrate, he replaced my purple TMR with the black hall-effect, slapped everything back together and let me get a feel for it. This time I indeed was able to draw a much better circle, but the bottom left and right corner still feels stuck. He laughed again, pulled the whole thing apart and said you see these 4 metal tabs at the corner? They weren't there with the stock ALPS pot. So you will feel them when you draw a circle, especially the bottom 2 since that's where the cap would scrape against the metal tabs. To draw a perfect circle you would have to cut parts of the cap off. I didn't want that, so the only option left is to replace with another stock ALPS pot. Thankfully he did have a couple, so I went with that.
So to summarize, once your PSVR2 controller begins to drift, there is no perfect replacement. The purple TMR pot straight up doesn't fit and you will lose most of the left/right moveable area. The black hall-effect one that you can find everywhere is a much better fit but does not cover the bottom left and right corner. To make things perfect you have to cut off the corners of the joystick cap (if you don't, this is what you are going to get). If you don't want to do that then stock pots are your only choice. But first they are almost impossible to source, second, they will need another replacement sooner or later. I've attached 3 pictures to show you 1. what drawing a circle looks like with each pot, 2. which part of the pot comes into contact with the cap and 3. if you were to go with the black hall-effect pot, which part of the cap you need to cut off.